Underwater explorers no longer need to get their feet wet to uncover some of history's most notable shipwrecks. Oxygen tanks and flippers are being replaced by underwater robots. Sam Macdonald is the president of Deep Trekker, a Canadian company that makes underwater bots. Since Deep Trekker's creation in 2010, the company's robots have become a standard in the aquaculture industry, but, Macdonald says, that wasn't the original intent.

"One night I dropped a flashlight off my boat and I started thinking about having an underwater robot that we could do things with including retrieving lost items, but also for exploring all of these ship wrecks," Macdonald said.

Macdonald got the chance to fulfill her wish this summer, when one of Deep Trekker's customers invited her along on an expedition to explore the USS Arizona, 75 years after it was sunk during the attack on Pearl Harbor. With the robot's help, Macdonald and the team were able to explore portions of the ship that would have otherwise been inaccessible.

“We took the ROV and went into the main main bomb hole, the bomb that they believe is responsible for the final sinking of the ship. We deployed the ROV into that hole, and witnessed firsthand some of the collapsed infrastructure," Macdonald said.

Joining the team was one of the six remaining survivors of the USS Arizona, who had a chance to get a live view of the admiral's cabin, a portion of the ship that had been off-limits to him.

Macdonald says the underwater bots have also been used to explore the HMS Erebus, one of the ships used by Sir John Franklin in 1845 when he set sail from England in search of a Northwest Passage across Canada's Arctic. According to oral testimony, the ship got stuck in the Arctic's thick ice and never made it to its final destination. Two years after the discovering the Erebus, explorers found the expedition's second ship: the HMS Terror. Macdonald says they will be exploring that ship this summer.